That depends on your cabinets and your current layout. It's one thing if your cabinets are all along one wall, and something else if your kitchen is L- or U-shaped.

Even good quality cabinetry is usually built to rely on a wall behind it to fasten into. There are ways around this, but expect a bit of messing around to make this work.

Have you tried simulating the extra depth with, say, a bit of cardboard? Can you still reach your upper cabinets easily?

Sure, I do it on 90% of my kitchen designs; deeper cabinets serve little purpose and the space behind standard depth cabinets is often useful for plumbing and downdraft exhaust vents.

You can also use a standard counter top and 6" or higher backsplash with a shelf at the top of the backsplash to help organize the things that inevitably collect at the back of the counter.

This arrangement puts the upper cabinets in a good position because you can see more of the counter when standing close to it and it is not more difficult to reach things in the upper cabinets because you can simply lean forward against the lower cabinets.

If you use undercabinet lighting be sure to explain to the electrician that the light should be at the front edge of the upper cabinet rather than at the back so it can light the counter better and not put a hot spot of light on the back wall.

Here is one that was finished recently. It's a bit difficult to see the shelf clearly because of the dark soapstone. I usually use a 1" thick maple shelf with a bullnose front edge.

You'd probably want to screw 2x4s into the wall to rest the back edge of the counter on.

My granite countertops are mostly 24" deep, some with 27" bumpouts (cooktop and sink). My island has 27" deep on both lower portion and raised 'bar' portion. (All on standard depth cabinets.) The 8.5' eating bar has a steel reinforcing beam

Will you have adequate aisles if you increase the countertop depths?

mightyanvil -- I like those countertop shelves!

Very nice kitchen mightyanvil.

If I want/need to use standard depth cabinets but have a deeper counter, what do I do to push the wall out BEFORE putting up the sheetrock? There's a big drainpipe to work around.

fern4
I don't understand what kind of problem you are tying to solve.